cfg80211: save multi-bssid properties

When the new IEs are generated, the multiple BSSID elements
are not saved. Save aside properties that are needed later
for PS.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Change-Id: I91d0e1bce4ce0387ce16b90d51c27519907fb406
CRs-fixed: 2399972
Git-commit: 0cd01efb03396c5368b1a32eed0ccb2aa453bdc8
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next.git


Signed-off-by: Peng Xu <pxu@codeaurora.org>